Megatest

  (let ((best     #f)
	(bestsize 0))
    (for-each 
     (lambda (disk-num)
       (let* ((dirpath    (cadr (assoc disk-num disks)))
	      (freespc    (cond
			   ((not (directory? dirpath))
			    (if (common:low-noise-print 50 "disks not a dir " disk-num)
			    (if (common:low-noise-print 300 "disks not a dir " disk-num)
				(debug:print 0 "WARNING: disk " disk-num " at path \"" dirpath "\" is not a directory - ignoring it."))
			    -1)
			   ((not (file-write-access? dirpath))
			    (if (common:low-noise-print 50 "disks not writeable " disk-num)
			    (if (common:low-noise-print 300 "disks not writeable " disk-num)
				(debug:print 0 "WARNING: disk " disk-num " at path \"" dirpath "\" is not writeable - ignoring it."))
			    -1)
			   ((not (eq? (string-ref dirpath 0) #\/))
			    (if (common:low-noise-print 50 "disks not a proper path " disk-num)
			    (if (common:low-noise-print 300 "disks not a proper path " disk-num)
				(debug:print 0 "WARNING: disk " disk-num " at path \"" dirpath "\" is not a fully qualified path - ignoring it."))
			    -1)
			   (else
			    (get-df dirpath)))))
	 (if (> freespc bestsize)
	     (begin
	       (set! best     (cons disk-num dirpath))